1. Field of the Invention
This invention relates to a radar device and an object detection method, and more particularly to an improved radar device and object detection method, which are able to detect the metals possessed by a person.
2. Description of the Related Art
It becomes necessary in security protection to watch whether or not a person hides a camera at the entrance of a facility, such as an institute, for example, which needs to be maintained secret. A conventional metal detecting method used in the field of such security protection employs X-radiation, a high frequency oscillation, magnetism, or the like.
A well-known metal detection device employing such a conventional metal detecting method, however, has the disadvantage that it cannot detect metals without fully approaching the same. A millimeter wave radar device has been proposed as a device, which can detect metals without closely approaching the same. A proposed millimeter wave radar device is mounted into an automobile to detect another automobile dozens of meters away from the radar device. It is theoretically assumed that other body reflecting electric wave (background) does not exist in neighborhood of the another automobile to be detected. Accordingly, it is difficult to distinguish a person possessing metals from a person possessing no metals at gateway because a reflected wave from the person is also simultaneously detected when the person hides the metals.